29 #ifndef _GLIBCXX_EXPERIMENTAL_OPTIONAL
30 #define _GLIBCXX_EXPERIMENTAL_OPTIONAL 1
38 #if __cplusplus <= 201103L
43 #include <type_traits>
51 namespace std _GLIBCXX_VISIBILITY(default)
53 namespace experimental
55 inline namespace fundamentals_v1
57 _GLIBCXX_BEGIN_NAMESPACE_VERSION
70 #define __cpp_lib_experimental_optional 201411
75 template<
typename _Tp>
80 struct in_place_t { };
83 constexpr in_place_t in_place { };
102 constexpr nullopt_t nullopt { nullopt_t::_Construct::_Token };
110 class bad_optional_access :
public logic_error
113 bad_optional_access() : logic_error(
"bad optional access") { }
116 explicit bad_optional_access(
const char* __arg) : logic_error(__arg) { }
118 virtual ~bad_optional_access() noexcept = default;
122 __throw_bad_optional_access(const
char*)
123 __attribute__((__noreturn__));
127 __throw_bad_optional_access(const
char* __s)
128 { _GLIBCXX_THROW_OR_ABORT(bad_optional_access(__s)); }
130 template<
typename _Tp,
typename =
void>
133 template<
typename _Tp>
134 struct _Has_addressof_mem<_Tp,
135 __void_t<decltype( std::declval<const _Tp&>().operator&() )>
139 template<
typename _Tp,
typename =
void>
142 template<
typename _Tp>
143 struct _Has_addressof_free<_Tp,
144 __void_t<decltype( operator&(std::declval<const _Tp&>()) )>
155 template<
typename _Tp>
156 struct _Has_addressof
157 : std::__or_<_Has_addressof_mem<_Tp>, _Has_addressof_free<_Tp>>::type
166 template<typename _Tp, enable_if_t<!_Has_addressof<_Tp>::value,
int>...>
167 constexpr _Tp* __constexpr_addressof(_Tp& __t)
173 template<typename _Tp, enable_if_t<_Has_addressof<_Tp>::value,
int>...>
174 inline _Tp* __constexpr_addressof(_Tp& __t)
189 template<
typename _Tp,
bool _ShouldProvideDestructor =
190 !is_trivially_destructible<_Tp>::value>
197 using _Stored_type = remove_const_t<_Tp>;
203 constexpr _Optional_base() noexcept
206 constexpr _Optional_base(nullopt_t) noexcept
207 : _Optional_base{} { }
210 constexpr _Optional_base(
const _Tp& __t)
211 : _M_payload(__t), _M_engaged(true) { }
213 constexpr _Optional_base(_Tp&& __t)
214 : _M_payload(std::move(__t)), _M_engaged(true) { }
216 template<
typename... _Args>
217 constexpr
explicit _Optional_base(in_place_t, _Args&&... __args)
218 : _M_payload(std::
forward<_Args>(__args)...), _M_engaged(true) { }
220 template<
typename _Up,
typename... _Args,
221 enable_if_t<is_constructible<_Tp,
222 initializer_list<_Up>&,
225 constexpr
explicit _Optional_base(in_place_t,
226 initializer_list<_Up> __il,
228 : _M_payload(__il, std::
forward<_Args>(__args)...),
232 _Optional_base(
const _Optional_base& __other)
234 if (__other._M_engaged)
235 this->_M_construct(__other._M_get());
238 _Optional_base(_Optional_base&& __other)
239 noexcept(is_nothrow_move_constructible<_Tp>())
241 if (__other._M_engaged)
242 this->_M_construct(std::move(__other._M_get()));
247 operator=(
const _Optional_base& __other)
249 if (this->_M_engaged && __other._M_engaged)
250 this->_M_get() = __other._M_get();
253 if (__other._M_engaged)
254 this->_M_construct(__other._M_get());
263 operator=(_Optional_base&& __other)
264 noexcept(__and_<is_nothrow_move_constructible<_Tp>,
265 is_nothrow_move_assignable<_Tp>>())
267 if (this->_M_engaged && __other._M_engaged)
268 this->_M_get() = std::move(__other._M_get());
271 if (__other._M_engaged)
272 this->_M_construct(std::move(__other._M_get()));
282 if (this->_M_engaged)
283 this->_M_payload.~_Stored_type();
289 constexpr
bool _M_is_engaged() const noexcept
290 {
return this->_M_engaged; }
295 {
return _M_payload; }
298 _M_get() const noexcept
299 {
return _M_payload; }
303 template<
typename... _Args>
305 _M_construct(_Args&&... __args)
306 noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
309 _Stored_type(std::
forward<_Args>(__args)...);
310 this->_M_engaged = true;
316 this->_M_engaged =
false;
317 this->_M_payload.~_Stored_type();
324 if (this->_M_engaged)
329 struct _Empty_byte { };
331 _Empty_byte _M_empty;
332 _Stored_type _M_payload;
334 bool _M_engaged =
false;
339 template<
typename _Tp>
340 class _Optional_base<_Tp, false>
343 using _Stored_type = remove_const_t<_Tp>;
346 constexpr _Optional_base() noexcept
349 constexpr _Optional_base(nullopt_t) noexcept
350 : _Optional_base{} { }
352 constexpr _Optional_base(
const _Tp& __t)
353 : _M_payload(__t), _M_engaged(true) { }
355 constexpr _Optional_base(_Tp&& __t)
356 : _M_payload(std::move(__t)), _M_engaged(true) { }
358 template<
typename... _Args>
359 constexpr
explicit _Optional_base(in_place_t, _Args&&... __args)
360 : _M_payload(std::
forward<_Args>(__args)...), _M_engaged(true) { }
362 template<
typename _Up,
typename... _Args,
363 enable_if_t<is_constructible<_Tp,
364 initializer_list<_Up>&,
367 constexpr
explicit _Optional_base(in_place_t,
368 initializer_list<_Up> __il,
370 : _M_payload(__il, std::
forward<_Args>(__args)...),
373 _Optional_base(
const _Optional_base& __other)
375 if (__other._M_engaged)
376 this->_M_construct(__other._M_get());
379 _Optional_base(_Optional_base&& __other)
380 noexcept(is_nothrow_move_constructible<_Tp>())
382 if (__other._M_engaged)
383 this->_M_construct(std::move(__other._M_get()));
387 operator=(
const _Optional_base& __other)
389 if (this->_M_engaged && __other._M_engaged)
390 this->_M_get() = __other._M_get();
393 if (__other._M_engaged)
394 this->_M_construct(__other._M_get());
402 operator=(_Optional_base&& __other)
403 noexcept(__and_<is_nothrow_move_constructible<_Tp>,
404 is_nothrow_move_assignable<_Tp>>())
406 if (this->_M_engaged && __other._M_engaged)
407 this->_M_get() = std::move(__other._M_get());
410 if (__other._M_engaged)
411 this->_M_construct(std::move(__other._M_get()));
422 constexpr
bool _M_is_engaged() const noexcept
423 {
return this->_M_engaged; }
427 {
return _M_payload; }
430 _M_get() const noexcept
431 {
return _M_payload; }
433 template<
typename... _Args>
435 _M_construct(_Args&&... __args)
436 noexcept(is_nothrow_constructible<_Stored_type, _Args...>())
439 _Stored_type(std::
forward<_Args>(__args)...);
440 this->_M_engaged = true;
446 this->_M_engaged =
false;
447 this->_M_payload.~_Stored_type();
453 if (this->_M_engaged)
458 struct _Empty_byte { };
461 _Empty_byte _M_empty;
462 _Stored_type _M_payload;
464 bool _M_engaged =
false;
470 template<
typename _Tp>
472 :
private _Optional_base<_Tp>,
473 private _Enable_copy_move<
475 is_copy_constructible<_Tp>::value,
477 __and_<is_copy_constructible<_Tp>, is_copy_assignable<_Tp>>::value,
479 is_move_constructible<_Tp>::value,
481 __and_<is_move_constructible<_Tp>, is_move_assignable<_Tp>>::value,
485 static_assert(__and_<__not_<is_same<remove_cv_t<_Tp>, nullopt_t>>,
486 __not_<is_same<remove_cv_t<_Tp>, in_place_t>>,
487 __not_<is_reference<_Tp>>>(),
488 "Invalid instantiation of optional<T>");
491 using _Base = _Optional_base<_Tp>;
494 using value_type = _Tp;
501 operator=(nullopt_t) noexcept
507 template<
typename _Up>
508 enable_if_t<is_same<_Tp, decay_t<_Up>>::value, optional&>
511 static_assert(__and_<is_constructible<_Tp, _Up>,
512 is_assignable<_Tp&, _Up>>(),
513 "Cannot assign to value type from argument");
515 if (this->_M_is_engaged())
516 this->_M_get() = std::forward<_Up>(__u);
518 this->_M_construct(std::forward<_Up>(__u));
523 template<
typename... _Args>
525 emplace(_Args&&... __args)
527 static_assert(is_constructible<_Tp, _Args&&...>(),
528 "Cannot emplace value type from arguments");
531 this->_M_construct(std::forward<_Args>(__args)...);
534 template<
typename _Up,
typename... _Args>
535 enable_if_t<is_constructible<_Tp, initializer_list<_Up>&,
537 emplace(initializer_list<_Up> __il, _Args&&... __args)
540 this->_M_construct(__il, std::forward<_Args>(__args)...);
547 swap(optional& __other)
548 noexcept(is_nothrow_move_constructible<_Tp>()
549 && noexcept(
swap(declval<_Tp&>(), declval<_Tp&>())))
553 if (this->_M_is_engaged() && __other._M_is_engaged())
554 swap(this->_M_get(), __other._M_get());
555 else if (this->_M_is_engaged())
557 __other._M_construct(std::move(this->_M_get()));
560 else if (__other._M_is_engaged())
562 this->_M_construct(std::move(__other._M_get()));
563 __other._M_destruct();
570 {
return __constexpr_addressof(this->_M_get()); }
578 {
return this->_M_get(); }
582 {
return this->_M_get(); }
586 {
return std::move(this->_M_get()); }
588 constexpr
const _Tp&&
590 {
return std::move(this->_M_get()); }
592 constexpr
explicit operator bool() const noexcept
593 {
return this->_M_is_engaged(); }
598 return this->_M_is_engaged()
600 : (__throw_bad_optional_access(
"Attempt to access value of a "
601 "disengaged optional object"),
608 return this->_M_is_engaged()
610 : (__throw_bad_optional_access(
"Attempt to access value of a "
611 "disengaged optional object"),
618 return this->_M_is_engaged()
619 ? std::move(this->_M_get())
620 : (__throw_bad_optional_access(
"Attempt to access value of a "
621 "disengaged optional object"),
622 std::move(this->_M_get()));
625 constexpr
const _Tp&&
628 return this->_M_is_engaged()
629 ? std::move(this->_M_get())
630 : (__throw_bad_optional_access(
"Attempt to access value of a "
631 "disengaged optional object"),
632 std::move(this->_M_get()));
635 template<
typename _Up>
637 value_or(_Up&& __u) const&
639 static_assert(__and_<is_copy_constructible<_Tp>,
640 is_convertible<_Up&&, _Tp>>(),
641 "Cannot return value");
643 return this->_M_is_engaged()
645 : static_cast<_Tp>(std::
forward<_Up>(__u));
648 template<
typename _Up>
650 value_or(_Up&& __u) &&
652 static_assert(__and_<is_move_constructible<_Tp>,
653 is_convertible<_Up&&, _Tp>>(),
654 "Cannot return value" );
656 return this->_M_is_engaged()
657 ? std::move(this->_M_get())
658 : static_cast<_Tp>(std::
forward<_Up>(__u));
663 template<
typename _Tp>
665 operator==(
const optional<_Tp>& __lhs,
const optional<_Tp>& __rhs)
667 return static_cast<bool>(__lhs) == static_cast<bool>(__rhs)
668 && (!__lhs || *__lhs == *__rhs);
671 template<
typename _Tp>
673 operator!=(
const optional<_Tp>& __lhs,
const optional<_Tp>& __rhs)
674 {
return !(__lhs == __rhs); }
676 template<
typename _Tp>
678 operator<(const optional<_Tp>& __lhs,
const optional<_Tp>& __rhs)
680 return static_cast<bool>(__rhs) && (!__lhs || *__lhs < *__rhs);
683 template<
typename _Tp>
685 operator>(
const optional<_Tp>& __lhs,
const optional<_Tp>& __rhs)
686 {
return __rhs < __lhs; }
688 template<
typename _Tp>
690 operator<=(const optional<_Tp>& __lhs,
const optional<_Tp>& __rhs)
691 {
return !(__rhs < __lhs); }
693 template<
typename _Tp>
695 operator>=(
const optional<_Tp>& __lhs,
const optional<_Tp>& __rhs)
696 {
return !(__lhs < __rhs); }
699 template<
typename _Tp>
701 operator==(
const optional<_Tp>& __lhs, nullopt_t) noexcept
704 template<
typename _Tp>
706 operator==(nullopt_t,
const optional<_Tp>& __rhs) noexcept
709 template<
typename _Tp>
711 operator!=(
const optional<_Tp>& __lhs, nullopt_t) noexcept
712 {
return static_cast<bool>(__lhs); }
714 template<
typename _Tp>
716 operator!=(nullopt_t,
const optional<_Tp>& __rhs) noexcept
717 {
return static_cast<bool>(__rhs); }
719 template<
typename _Tp>
721 operator<(const optional<_Tp>& , nullopt_t) noexcept
724 template<
typename _Tp>
726 operator<(nullopt_t, const optional<_Tp>& __rhs) noexcept
727 {
return static_cast<bool>(__rhs); }
729 template<
typename _Tp>
731 operator>(
const optional<_Tp>& __lhs, nullopt_t) noexcept
732 {
return static_cast<bool>(__lhs); }
734 template<
typename _Tp>
736 operator>(nullopt_t,
const optional<_Tp>& ) noexcept
739 template<
typename _Tp>
741 operator<=(const optional<_Tp>& __lhs, nullopt_t) noexcept
744 template<
typename _Tp>
746 operator<=(nullopt_t, const optional<_Tp>& ) noexcept
749 template<
typename _Tp>
751 operator>=(
const optional<_Tp>& , nullopt_t) noexcept
754 template<
typename _Tp>
756 operator>=(nullopt_t,
const optional<_Tp>& __rhs) noexcept
760 template<
typename _Tp>
762 operator==(
const optional<_Tp>& __lhs,
const _Tp& __rhs)
763 {
return __lhs && *__lhs == __rhs; }
765 template<
typename _Tp>
767 operator==(
const _Tp& __lhs,
const optional<_Tp>& __rhs)
768 {
return __rhs && __lhs == *__rhs; }
770 template<
typename _Tp>
772 operator!=(
const optional<_Tp>& __lhs, _Tp
const& __rhs)
773 {
return !__lhs || !(*__lhs == __rhs); }
775 template<
typename _Tp>
777 operator!=(
const _Tp& __lhs,
const optional<_Tp>& __rhs)
778 {
return !__rhs || !(__lhs == *__rhs); }
780 template<
typename _Tp>
782 operator<(const optional<_Tp>& __lhs,
const _Tp& __rhs)
783 {
return !__lhs || *__lhs < __rhs; }
785 template<
typename _Tp>
787 operator<(const _Tp& __lhs, const optional<_Tp>& __rhs)
788 {
return __rhs && __lhs < *__rhs; }
790 template<
typename _Tp>
792 operator>(
const optional<_Tp>& __lhs,
const _Tp& __rhs)
793 {
return __lhs && __rhs < *__lhs; }
795 template<
typename _Tp>
797 operator>(
const _Tp& __lhs,
const optional<_Tp>& __rhs)
798 {
return !__rhs || *__rhs < __lhs; }
800 template<
typename _Tp>
802 operator<=(const optional<_Tp>& __lhs,
const _Tp& __rhs)
803 {
return !__lhs || !(__rhs < *__lhs); }
805 template<
typename _Tp>
807 operator<=(const _Tp& __lhs, const optional<_Tp>& __rhs)
808 {
return __rhs && !(*__rhs < __lhs); }
810 template<
typename _Tp>
812 operator>=(
const optional<_Tp>& __lhs,
const _Tp& __rhs)
813 {
return __lhs && !(*__lhs < __rhs); }
815 template<
typename _Tp>
817 operator>=(
const _Tp& __lhs,
const optional<_Tp>& __rhs)
818 {
return !__rhs || !(__lhs < *__rhs); }
821 template<
typename _Tp>
823 swap(optional<_Tp>& __lhs, optional<_Tp>& __rhs)
824 noexcept(noexcept(__lhs.swap(__rhs)))
825 { __lhs.swap(__rhs); }
827 template<
typename _Tp>
828 constexpr optional<decay_t<_Tp>>
829 make_optional(_Tp&& __t)
830 {
return optional<decay_t<_Tp>> { std::forward<_Tp>(__t) }; }
833 _GLIBCXX_END_NAMESPACE_VERSION
838 template<
typename _Tp>
839 struct hash<experimental::optional<_Tp>>
841 using result_type = size_t;
842 using argument_type = experimental::optional<_Tp>;
845 operator()(
const experimental::optional<_Tp>& __t)
const
846 noexcept(noexcept(hash<_Tp> {}(*__t)))
850 constexpr
size_t __magic_disengaged_hash =
static_cast<size_t>(-3333);
851 return __t ? hash<_Tp> {}(*__t) : __magic_disengaged_hash;
858 #endif // _GLIBCXX_EXPERIMENTAL_OPTIONAL
void swap(basic_filebuf< _CharT, _Traits > &__x, basic_filebuf< _CharT, _Traits > &__y)
Swap specialization for filebufs.
complex< _Tp > operator*(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x times y.
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
_Tp * __addressof(_Tp &__r) noexcept
Same as C++11 std::addressof.
void _Construct(_T1 *__p, _Args &&...__args)